Early warning system for bio-terror

The aim is to provide information that could be used to save thousands of lives if terrorists launch a biological or chemical attack on the US.

Doctors would be able to use the data to gain a head start in treating and isolating outbreaks of infectious disease - an area where speed is crucial if death rates are to be minimised.

The Centers for Disease Control and Prevention will lead the multi-million dollar project to build a computerised network that will enable experts to track medical data on residents of eight major US cities.

The national network will help health authorities spot disease outbreaks by tracking doctors' reports, admissions to hospital casualty depatments and sales of medication.

A senior US official told the New York Times: "Our goal is to have a model that any city could pick up and apply."

However, officials have refused to say which cities will be involved.

The initiative, to which President George W. Bush is expected to refer in his "State of the Union" address on Tuesday, marks the latest phase in attempts by US authorities to ready the country for a bioterrorist attack.

Monitoring stations

Last week US Environmental Protection Agency officials said monitoring stations now used to check air pollution would be fitted with filters to detect biological agents.

A network of laboratories will analyse results which raise concern and come up with answers within 24 hours, they said.

Meanwhile, smallpox vaccine is being made available to any US citizen who wants it.